Chyle (; ) is a milky
bodily fluid
Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the body of an organism. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in wom ...
consisting of
lymph and emulsified
fat
In nutrition science, nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such chemical compound, compounds, most commonly those that occur in living beings or in food.
The term often refers specif ...
s, or free
fatty acid
In chemistry, in particular in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated and unsaturated compounds#Organic chemistry, saturated or unsaturated. Most naturally occurring fatty acids have an ...
s (FFAs). It is formed in the
small intestine
The small intestine or small bowel is an organ (anatomy), organ in the human gastrointestinal tract, gastrointestinal tract where most of the #Absorption, absorption of nutrients from food takes place. It lies between the stomach and large intes ...
during digestion of fatty foods, and taken up by
lymph vessels specifically known as
lacteals. The lipids in the chyle are
colloid
A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others exte ...
ally suspended in
chylomicrons.
Clinical significance
A chyle
fistula
In anatomy, a fistula (: fistulas or fistulae ; from Latin ''fistula'', "tube, pipe") is an abnormal connection (i.e. tube) joining two hollow spaces (technically, two epithelialized surfaces), such as blood vessels, intestines, or other h ...
occurs when defect(s) of lymphatic vessel(s) result in leakage of lymphatic fluid, typically accumulating in the thoracic (pleural) or abdominal (peritoneal) cavities, leading to a chylous pleural effusion (
chylothorax) or
chylous ascites, respectively.
Diagnosis of a chyle fistula may be accomplished by analysis of pleural/peritoneal fluid. Identifying the source (localizing the lymphatic defect) is often challenging, but may be accomplished with lymphangiography, which is occasionally associated with a serendipitous therapeutic effect (resolution of the leak), thought to be secondary to a sclerosant effect of the lymphangiography contrast.
Due to the extreme
friability of the lymphatic vessels, direct repair of defects is impractical. Therefore, treatment of chyle fistulae relies upon either decreased production of lymphatic fluid to allow for healing of lymphatic defect(s) or permanent diversion of lymphatic fluid away from lymphatic defect(s). Decreased production of lymphatic fluid may be accomplished by dietary restriction (or complete replacement of oral intake with
total parenteral nutrition
Parenteral nutrition (PN), or intravenous feeding, is the feeding of nutritional products to a person intravenously, bypassing the usual process of eating and digestion. The products are made by pharmaceutical compounding entities or standard pha ...
), as well as by the medications
octreotide (a synthetic analogue of the hormone
somatostatin
Somatostatin, also known as growth hormone-inhibiting hormone (GHIH) or by #Nomenclature, several other names, is a peptide hormone that regulates the endocrine system and affects neurotransmission and cell proliferation via interaction with G ...
)
[{{Cite journal, pmid=15830574, year=2005, last1=Mincher, first1=L, last2=Evans, first2=J, last3=Jenner, first3=MW, last4=Varney, first4=VA, title=The successful treatment of chylous effusions in malignant disease with octreotide, volume=17, issue=2, pages=118–21, journal=Clinical Oncology, doi=10.1016/j.clon.2004.06.016] and
orlistat (a lipase inhibitor that decreases absorption of dietary fats). Permanent diversion of lymphatic fluid may be accomplished by
thoracic duct embolization (a needle-based procedure to occlude the duct by depositing glue/embolic material into it) or by thoracic duct ligation (an open surgical procedure to occlude the duct by suturing tightly around it).
See also
*
Chyme
Chyme or chymus (; ) is the semi-fluid mass of partly digested food that is expelled by the stomach, through the pyloric valve, into the duodenum (the beginning of the small intestine).
Chyme results from the mechanical and chemical breakdown ...
References
Body fluids
Digestive system
Lymphatic system